1. Field of the Invention
The present invention relates to a belt type continuous casting machine, and more particularly to such casting machine provided with synchronous variable-width side dams.
2. Description of the Prior Art
One example of a belt type continuous casting machine in the prior art is shown in FIGS. 7 and 8, the latter figure being a vertical cross-sectional view taken along line VIII--VIII in the former figure as viewed in the direction of the arrows therein. As will be seen from these figures, the casting machine is composed of principal component members such as a pair of water-cooled belts 3 disposed in parallel to each other and spaced by a distance corresponding to a thickness T of a cast piece 21 to be manufactured, tension pulleys 1 supported by respective vertically movable bearing boxes 5 and having the belts 3 wound therearound, drive pulleys 2 supported by respective fixedly disposed bearing boxes 6, and side members or dams 4 fixedly disposed so that the belts 3 are slidable over and pinch therebetween the side dams 4.
The water-cooled belts 3 and the side dams 4 are provided with respective water-cooling devices, not shown, so that solidification heat absorbed from molten metal 20 may be cooled thereby. The tension pulleys 1 are associated with a pulling device, not shown, for pulling them upwards, as viewed in the drawings, such as air cylinders, by the intermediary of the bearing boxes 5, while the drive pulleys 2 are associated with a driving device, not shown.
By means of such driving device, the two water-cooled belts 3 are moved or rotated via the drive pulleys 2 in directions indicated by arrows .alpha. and slide along the side dams 4, and molten metal 20 is continuously fed into the mold section formed of the side dams 4 and the water-cooled belts 3. Reference numeral 20a designates a top surface of the molten metal 20. The molten metal 20 is cooled and solidified by the water-cooled belts 3 moving downwards as viewed in the drawings at an appropriate speed and by the fixed side dams 4. The thus solidified metal is discharged or ejected as cast piece 21 downwards as viewed in the drawings as shown by an arrow .beta. at a speed substantially equal to the linear speed of the water-cooled belts 3, and then it is sent to the next step of the process.
Another example of a belt type continuous casting machine in the prior art is shown in FIGS. 9 and 10, the latter figure being a vertical cross-sectional view taken along line X--X in the former figure as viewed in the direction of the arrows therein. As will be seen from these figures, the casting machine is composed of principal component members such as a pair of water-cooled belts 3 disposed in parallel to each other and spaced by a distance corresponding to a thickness T of a cast piece 21 to be manufactued, tension pulleys 1 supported by respective vertically movable bearing boxes 5 and having the belts 3 wound therearound, drive pulleys 2 supported by respective fixedly disposed bearing boxes 6, and a pair of movable type side members or dams 7 pinched between the two belts 3.
Each of the side dams 7 consists of a large number of metal blocks 7a which are constrained on a continuous flexible metal belt 7b with their adjacent ends held in a face-to-face relationship. The water-cooled belts 3 and the side dams 7 are provided with respective water-cooling devices not shown so that solidification heat absorbed from molten metal 20 may be cooled thereby. The tension pulleys 1 are associated with a pulling device, not shown, for pulling them upwards, as viewed in the drawings, such as air cylinders, by the intermediary of the bearing boxes 5, while the drive pulleys 2 are associated with a driving device, not shown.
When both water-cooled belts 3 are moved or rotated in directions indicated by arrows .alpha. via the drive pulleys 2 by means of the driving, device, the two side dams 7 are moved in the direction indicated by an arrow .gamma. due to a pinching force of the water-cooled belts 3. Molten metal 20 is continuously fed into the mold section formed of the water-cooled belts 3 and side dams 7. The molten metal 20 is cooled and solidified by the water-cooled belts 3 and the side dams 7 moving downwards as viewed in the drawings at an appropriate speed. The thus solidified metal is discharged or ejected as a cast piece 21 downwards as viewed in the drawings as shown by an arrow .beta. at a speed substantially equal to the linear speed of the water-cooled belts 3, and then it is sent to the next step of the process.
The fixed type side dams 4 shown in FIGS. 7 and 8 involve the problem that they are liable to cause seizure when the moving molten metal 20 solidifies. In addition, both such fixed type side dams 4 and the movable type side dams 7 shown in FIGS. 9 and 10 have a shortcoming that, during a continuous casting operation, a change in the width of the cast piece 21 is not possible. Accordingly, with either the casting machine shown in FIGS. 7 and 8 or that shown in FIGS. 9 and 10, in order to change the width of the cast piece 21, it is necessary to employ complicated operations including interruption of pouring of the molten metal, and after discharge of the cast piece 21, changing the positions of the side dams 4 or 7 are change, and then again starting casting. The resultant loss of time is tremendous.